1. Technical Field
Various embodiments generally relate to a semiconductor integrated circuit, and more particularly, to a write driver, a variable resistance memory apparatus including the same, and an operation method.
2. Related Art
Among nonvolatile memories, variable resistance memory elements such as the phase change RAM and the resistive RAM define information storage states according to the resistant state of the data storage material. In the variable resistance memory elements, program current is applied in a program operation in such a manner that the data storage material may have a desired resistant state.
A decrease in a rising slope of the program current pulse means that a required amount of current is not transferred to a target cell and target data is not written. Therefore, in order to write the target data, it is necessary to repeat program and verify processes several times.
Under this situation, a method of compensating for a program current pulse in consideration of a time constant determined according to a path from a write driver to a cell may be adopted. However, if only a time constant determined according to a path from a write driver to a cell is considered, an overshoot phenomenon is likely to occur according to the resistant state of the cell before program.